Astronomy > What do you know about Stars?

ANSWER: all of the above

The more massive a star is, the hotter it burns. The hotter it burns, the faster a star uses up its fuel and the shorter its life is. The hottest and most massive stars are blue and bright. The coolest and least massive stars are red and dim.

ANSWER: First a, then b.

Most dying stars—including our Sun—will become red giants, then white dwarfs. It takes billions of years for the white dwarfs to cool down and fade away. 99% of stars end their lives like this.

ANSWER: supernova

It's very rare for a star to "go supernova." Only about 1% of stars are massive enough to explode as one. Supernovas occur somewhere in the Milky Way Galaxy once every 50-100 years on average.

ANSWER: more massive than average

Surprise! The Sun is not your average star. It is a middle-aged yellow star that is more massive than nearly 90% of stars.

ANSWER: 98.6%

Our Sun is the hulk of our Solar System . The other 1.4% is in the planets, moons, asteroids, comets, gas, and dust that orbit the Sun.

ANSWER: 8 minutes

Light travels incredibly fast—at a speed of 186,000 miles per second. Sunlight reaches us about 8 minutes after it leaves the Sun. A light-year  is the distance light travels in one year.

ANSWER: 250 million years

It takes one "Galactic Year," or 250 million years, for our Solar System to circle the center of the spiral-shaped galaxy once. Dinosaurs first appeared about one Galactic Year ago! The Earth formed 18 Galactic Years ago.

ANSWER: on Earth and in space

To study stars near and far, astronomers analyze their light using telescopes on Earth and in space. In the universe as far as our telescopes can ever see, there are perhaps 20,000,000,000,000,000,000,000 stars! Or more.